Albert schlumberger



* NITED STATES PATENT OFFICE.

ALBERT'SOIILUMBERGER, OF PARIS, FRANCE.

WHITE SAFETY- PAPER SPECIFICATION forming part of Letters Patent No.443,116, dated December 23, 1890.

Application filed August 21, 1889. Serial No. 321,521. (No specimens.)Patentedin France April 4, 1888, No. 194,222 in Belgium July 10,1888,110. 82,515; in Austria-Hungary October 18, 1888, No. 9,662, and inSpain March 4,1889,N0.9,320.

To all whom. it may cancer/L.-

Be it known that I, ALBERT SCHLUMBERGER, a citizen of the Republic ofFrance, residing at Paris, France, have invented a new and usefulImprovement in the Art of Making lVhite Safety-Paper, (for which I haveobtained patents in France April 4., 1888, No. 194,222; in Belgium July10, 1888, No. 82,515; in Austria-Hungary October 13, 1888, No. 9,662,and in Spain March at, 1889, No. 9,320,) of which the following is aspecification.

This invention relates to the preparation of a white safety-paper, bymeans of which the records writ-ten thereon cannot be forged or alteredby means of acid or chloride of lime without the production of blue orbrown spots. My invention consists,essentially,in apaper impregnatedwith several ingredients in the form of resin compounds of metallicsalts e. g., a resinated ferrous-oxide salt with a mixture of a resincompound of plumbic ferrocyanide (or ferro-cyanide of tin) and a resincompound of ferro-cyanide of manganese.

To form a very sensitive safety-paper I also add to the above mixture amixture-of resin compound of molybdenum salt or of resin compound ofcadmium oxide, to which is added a specially-prepared compound ofresinated sulphide of zinc, the whole worked together into the'papeupulpwith a little borax having an alkaline reaction. Ordinarily the additionof an iron salt to ferro-cyanide of potassium would color the paper-pulpblue, especially when at the completion of the manufacture the resinsoap is decomposed by means of alum, as is done in coloring paper. Thiscolor is prevented by the isolating property of the resin compound ofmetallic salts, which in this instance is of prime importance. In orderto fix the zinc sulphide direct-1y upon the fibers a portion of thepaper-pulp used is stirred with a quantity of zinc sulphate, and is thenmixed with resin soap and sodium sulphydrate. All these resin compoundsare introduced for the purpose of causing the differentmetallicprccipitates in alkaline state to adhere readily to the fibers.Otherwise the nonresinated individual precipitates would during theprocess of manufacture mostly disappear and a worthless safety-paperwould be produced.

The proportions of the different salts which I regard as best for thepreparation of fifty kilos of paper are as follows: To a mass of onehundred and fiftykilos of paper-pulp,bleached and cleaned in the usualmanner and which contains fifty kilos of dried paper fiber, there areadded, preferably during the sizing operation of the machinery, thefollowing ingredients:

First. One hundred to one hundred and fifty grams sulphate of iron,which is dissolved in a small quantity of water and is mixed with asmall excess of resin soap. The precipitate thus produced isreddish-brown, but being small in quantity it does not affect the colorof the paper, especially after the same has passed through the ordinarybluing operation.

Second. Then a mixture of six hundred to seven hundred grams borax, ninehundred to onethousand grams potassic cyanide dissolved in twenty litersof water, mixed with so much resin soap as will cause one kilo of resinto be present in the above-named soap solution.

Third. After the paper mass has been thoroughly stirred with this resincompound a solution of four hundred to five hundred grams plumbicacetate or zinc chloride in ten liters of water is added.

Fourth. The stirring is then continued and the following mixture isadded: (a) ten liters of water and eight hundred to one thousand gramsferro-cyanide of potassium mixed with (b) one thousand to one thousandtwo hundred grams manganio sulphate of chloride. The reaction arising atthis stage of the process is expressed in the following equation:

2.FeCy -)K.

b 1 (sulphate of (form-cyanide of potassium) manganese) Pb(FeCy-)MntFeCy 2(C,H OQK 3K S0. (ferro-cyariide (term-cyanide (aceta te of(sulphateof of lead) of manganese) potash) potash) soap containing threekilos of resin, is added to the mass of the pulp. If a salt ofmolybdenum or cadmium is to be used, then in the former case about fourhundred grams of ammonium molybdenate are taken, decomposed by anequivalent quantity of lead acetate, and added to the above mass. Thereaction thus arising is expressed in the following equation:

2(Fety oh', -i' )lo,,.\ll, i -l(( ,ll,,(). .r3lh .llnhlh (ferro-cyanide(molybdenate (acetate of (sulphate of of potash) of ammonium) lead)manganese) PMFeCyyf I lhTilo, )Im'FeCy.) (ferro'cyanide oJ' (molybdenate(manganie lead of lead) lerroevanide) Cadmium salt, on the contrary, isadded to the manganese solution, and in the proportion of four hundredto live hundred grams. )Vhenever a molybdenum or cadmium salt isemployed, resinated zine sulphide is added, which becomes fixed upon thefiber, as above stated, so that at each acid reaction, in case offorgery or alteration, a brown or dark colored molybdenum or cadmiumsulphide is formed upon the paper.

The proportion of zinc sulphide added to the above mass, in connectionwith the molybdenum or cadmium salts, is preferablytwo hundred and fiftygrams for the above proportion of the ingredients.

Finally, and to complete the paper, the excess of resin soap which isnot combined with the above-namcd metallic salts is decomposed by meansof from three to [our kilos of alum, as is usualin practice forsizing,except, when the mass shows too acid a reaction, it is neutralized bymeans of live hundred grams of borax or sodic phosphate, the purpose ofthis addition being to fix the excess of alum in the form of a neutralprecipitate.

The following formulee and equations express the principal reactionsarising in the production of my safetypaper and when the same is actedon by acids or bleaching-powder (hypoehlorite of lime) for the purposeof effacing or altering any inscription thereon:

The addition of borax and an excess of resin soap have for object onlyto keep the mixture alkaline, so as to prevent the forma tion of bluebefore the application of the acids, &c., for the purposes ofalteration, as stated. )Vhen any of these acidssuch as muriatic oroxalic acidare employed there occurs a displacement of the resin soapfrom the iron compounds fixed into the paper and the ensuing acidulationgives rise to blue stains, due

to the contact of the iron compounds and the \Vhen hypochlorite of lime(bleachingpowdcr) is used, a brown stain, due to oxide of manganese,results, thus (a( )Cl-() llntFeCy Mm t tatl l- Fety (hypochlorite(prussiate of (oxide of (chloride 01'' (prnssie of lime) manganese)manganese) calcium) acid) Under the addition of a molybdenum salt-s, thereaction exemplified in the following equation occurs in the pulp:

2 FeC .,)K, M xu, autunmpzrh .lInS(),: (prussiateot (molybdateot(acetate of (sulphate of potash) ammonia) lead) manganese) lbWeCXH) 4llfllq, Mn(Fe( v.,)+ (prussiate ol' (molybdate ol' (prussiate of lead)lead) manganese) It. is understood, of course, that the entire mixturecomprising the ferrated paper-pulp is in an alkaline state. (Resin soapand borax in excess.) Acid acting on the paper so prepared andcontaining sulphide of zinc forms: Mo S-l-PbS (sulphide of molybdenumand sulphide of lead) as a brown sulphide stain. At the same time theacid acting on the ferro-cyanic acid evolved from the prussiate of leadand of manganese yields a blue stain with the iron oxide in the paper.

Bleaching-powder produces brown stains, due to oxide of manganese, asalready explained in connection with the first process.

Ilaving thus described my invention, what I claim, and desire to secureby Letters Patent, is

1. A white safety-paper impregnated with resinated ferrous salt, a resincompound of plumbio ferro-cyanide, and a resin compound of ferro-cyanideof manganese, substantially as and for the purposes set forth.

2. A White safety-paper impregnated with a mixture of resin compounds ofmetallic salts, in combination with a molybdenum salt and a resincompound of zinc sulphide, substantially as and for the purposes setforth.

3. A white safety-paper impregnated with a resinated ferrous salt, aresin compound of plumbie ferro-cyanide, and a resin compound offerro-cyanide of manganese, in combination with a salt of molybdenum anda resin compound of zinc sulphide, substantially as and for the purposesset forth.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

ALBERT SCIILL'MUERGER.

Witnesses:

R. J. PRESTON, DAviD T. S. FULLER.

